Both Sony RX10 III and Panasonic ZS99 have 20.0 MP resolution sensors but Sony RX10 III's sensor is 1″ (13.2 x 8.8 mm ) and Panasonic ZS99's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Sony RX10 III's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Panasonic ZS99.
Below you can see the RX10 III and ZS99 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony RX10 III and Panasonic ZS99 Cameras
As seen above, Sony RX10 III has a 4.1x Larger sensor area than Panasonic ZS99. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Sony RX10 III
or the
Panasonic ZS99 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1″ versus 1/2.3-inch),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.
